1. Field of the Invention
This invention relates to a universal unit that can form three-dimensional structures of arbitrary shape by means of automatic self-configuration, and more concretely to a three-dimensional universal unit for movable structures that is suited to utilization in three-dimensional structures of arbitrary shape to be erected in outer space or other extreme environments, consisting of a plurality of universal units of identical structure which are coupled to each other and these couplings can be changed, released or recoupled without outside assistance, thereby forming the desired three-dimensional structure by itself.
2. Description of the Prior Art
When various types of work are necessary in extreme environments such as outer space, planetary exploration, deep sea or inside nuclear reactors where work by humans is difficult or undesirable, this work must be performed using robots. It has been envisioned that such robots would form various structures by coupling together a plurality of assembly units of identical structure, or by changing, releasing or recoupling the couplings among the assembly units. Such robots would typically couple, release, change or recouple the units with outside assistance. However, if such structures are in the aforementioned extreme environments or confined spaces or the like where outside assistance is difficult to obtain, it is difficult to couple, release, change or recouple the units. Regarding this technical topic, the present inventors have already developed a multi-function module used to constitute equipment (JP-B-8-1575).
The structures formed by means of these multi-function modules used to constitute equipment have a two-dimensional shape, and the modules, each equipped with an information processing unit, can be coupled to each other by electromagnetic force and the positions of the couplings can be changed or repulsive force can be generated to release the couplings, so by successively changing the relationship among couplings with the adjacent modules, it is possible to change the two-dimensional shape of the entire structure. Therefore, starting from an initial shape when coupled into an arbitrary two-dimensional shape, it is possible to change the relationship among couplings to make it into a structure having the target two-dimensional shape. This apparatus is constituted such that an upper-layer member, middle-layer member and lower-layer member with a plurality of central axisymmetric protruding arms at equal intervals are coaxially stacked, where the upper-layer member and lower-layer member are in the same phase around the central axis, while the middle-layer member is in the opposite phase. In addition, the protruding arms of the upper-layer member and lower-layer member are coupled at a distance at which the protruding arms of the middle-layer member of another module can be inserted between them, and an attracting or repelling coupling/uncoupling mechanism is provided between the protruding arms of opposing upper-layer members and lower-layer members and the protruding arms of middle-layer members of other modules, while an information processing apparatus is connected to each protruding arm and transmitters and receivers are provided in order to perform communication with other modules that are coupled by means of the coupling/uncoupling mechanism. However, if the shape is changed in only two dimensions, its applications are markedly limited, since a three-dimensionally arbitrary shape is required for a general structure.
In order to meet these needs, the present inventors have further developed a three-dimensional universal unit proposed in U.S. Pat. No. 5,988,845 and JP-A-10-110893.
With the aforementioned three-dimensional universal unit proposed by the present inventors, the modules used to constitute equipment which can be formed into an arbitrary two-dimensional shape without outside assistance as proposed above have evolved to a constitution such that they can be assembled into an arbitrary three-dimensional shape, so a plurality of universal units of identical structure can be coupled or these couplings can be released or changed, and thus the desired three-dimensional structure can be self-configured.
However, the aforementioned proposal describes constructing a structure at limited lattice points, and it is difficult to construct machines that have active components such as robot arms, hands or walking machines. In addition, the modules have a complex structure, making them very difficult to manufacture and expensive, there are many areas of mechanical friction and the number of components is large so the probability of failure becomes higher, among other problems.
The present invention was accomplished in consideration of the above problems and one object thereof is to provide a three-dimensional universal unit for movable structures that has a simple structure and can easily form machines having active components, that operates reliably in long-term usage and that can be manufactured inexpensively.
In order to achieve the aforementioned object, the three-dimensional universal unit for movable structures according to this invention comprises first and second coupling members, each of which comprises two opposing side surface parts, an end face part connected to form a right angle with one end face of each side surface part, a coupling/uncoupling device provided on the two side surface parts and end face part of the first coupling member and which operates independently, a permanent magnet provided on the two side surface parts and end face part of the second coupling member, and a linking part disposed between the two side surface parts of each coupling member; a linking member that rotatably links the linking parts of the two coupling members; and a drive apparatus that rotationally drives the coupling members relative to the linking member.
The coupling/uncoupling device comprises a top plate, a base plate disposed movably opposite to said top plate, a permanent magnet secured upon the base plate, a compression coil spring disposed between the base plate and the top plate that continuously pushes the two apart, and a shape memory spring disposed between the base plate and the top plate, wherein the shape memory spring takes two positions: a short first shape that does not contact one of the base plate and the top plate when the base plate is separated furthest from the top plate; and a long second shape that pushes in a direction separating the base plate and top plate when the base plate is closest to the top plate.
The compression coil spring may comprise a conical coil spring adapted to the attraction characteristics of the permanent magnet.
The drive apparatus that rotationally drives the coupling members may be provided on the side of the linking member.
Electrodes that are secured in the interior of the coupling members and that extend to the surface of the top plate may be provided.
As described above, the universal unit according to the present invention consists of two coupling members of a simple structure that are easily configured and a linking member that links the two coupling members. Accordingly, it can operate reliably in long-term usage and can be manufactured inexpensively.
The above and other objects and features of the invention will become apparent from the following description made with reference to the appended drawings.